This release is primarily aimed at fixing a variety of small bugs that have existed in Gallery for a few releases, as well as a couple of fairly serious bugs (including a very serious SECURITY bug that can lead to a remote exploit) that were introduced in the version 1.3.2. If you are using the 1.3.2 release we STRONGLY RECOMMEND that you upgrade to 1.3.3 as soon as possible to minimize the possibility of a web server compromise.
Download here.